This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Just got an android phone and studying for SCJP, so thought I would combine both to learn Android and SCJP at the same time. Its 100% free. I intend to add more questions and beef up the functionality, so keep an eye on it.
At the moment 240 questions with answers and tips.